/*
 * @(#)Subject.java
 *
 * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *   2. Redistribution in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed or intended for use in
 * the design, construction, operation or maintenance of any nuclear facility.
 */

package org.wso2.balana.ctx.xacml2;

import org.wso2.balana.attr.AttributeDesignator;

import java.net.URI;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

/**
 * This class represents the collection of <code>Attribute</code>s associated
 * with a particular subject.
 * 
 * @since 1.1
 * @author seth proctor
 */
public class Subject {

	// the subject's category
	private URI category;

	// the attributes associated with the subject
	private Set attributes;

	/**
	 * <code>URI</code> form of the default subject category
	 */
	public static final URI DEFAULT_CATEGORY;

	// the exception thrown if the default category was invalid
	private static RuntimeException earlyException = null;

	/**
	 * Tries to initialize the default category, keeping track of the exception
	 * for later use (if there was a problem). Note that this should never
	 * happen, but the error case will be reported correctly if the default
	 * string is invalid.
	 */
	static {
		URI defaultURI = null;

		try {
			defaultURI = new URI(AttributeDesignator.SUBJECT_CATEGORY_DEFAULT);
		} catch (Exception e) {
			earlyException = new IllegalArgumentException("invalid URI");
			earlyException.initCause(e);
		}

		DEFAULT_CATEGORY = defaultURI;
	}

	/**
	 * Creates a new collection of subject attributes using the default subject
	 * cateorgy.
	 * 
	 * @param attributes
	 *            a non-null <code>Set</code> of <code>Attribute</code> objects
	 */
	public Subject(Set attributes) {
		this(null, attributes);

		if (earlyException != null)
			throw earlyException;
	}

	/**
	 * Creates a new collection of subject attributes using the given subject
	 * category.
	 * 
	 * @param category
	 *            the subject category or null for the default category
	 * @param attributes
	 *            a non-null <code>Set</code> of <code>Attribute</code> objects
	 */
	public Subject(URI category, Set attributes) {
		if (category == null)
			this.category = DEFAULT_CATEGORY;
		else
			this.category = category;

		this.attributes = Collections.unmodifiableSet(new HashSet(attributes));
	}

	/**
	 * Returns the category of this subject's attributes.
	 * 
	 * @return the category
	 */
	public URI getCategory() {
		return category;
	}

	/**
	 * Returns the <code>Attribute</code>s associated with this subject.
	 * 
	 * @return the immutable <code>Set</code> of <code>Attribute</code>s
	 */
	public Set getAttributes() {
		return attributes;
	}

}
